Construction for magneto electric generators



Dec. 8, 1936. LE ROY s. DUNHAM x-:T AL. 2,053,083

CONSTRUCTION FOR MAGNETO-ELECTRIC GENERATORS Filed July 10, 1955 3 Sheets-Sheet l IN V EN TORS Dec. 8, 1936.

LE ROY S. DUNHAM ET AL.

CONSTRUCTION FOR MAGNETO-ELECTRIC GENERATORS s sheets-sheet 2 Filed July lO, 1955 .2

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CONSTRUCTION FOR MAGNETO-ELECTRIC GENERATORS Filed July l0, 1955 3 Sheets-Sheet 3 1N V EN TOR` m n. um T om A 5. aww.. R07. D2@

Patented Dec. 8, 1936 UNITED STATESy PATENT OFFICE CONSTRUCTION FOR MAGNETO ELECTRIC GENERATORS Application July 10,

20 Claims.

This invention relates to improvements in the design of magneto electric generators such as are used on internal combustion engines for furnishing ignition current therefor.

In the ordinary type of high-tension ignition generator, the circuit breaker is usually mounted in axial alignment with the rotor or rotating part of the machine, and the distributor for the ignition current is usually mounted above the circuit breaker which controls the primary circuit of the ignition generating coil.

Oi the various parts of an ignition generator, the circuit breaker as a general rule gives more trouble or requires more attention than any other part, because the ignition points on the circuit breaker wear away and have to be renewed; likewise, other associated parts forming the complete structure of the circuit breaker require attention. Where these circuit breaker parts are mounted at the lower portion of the generator, as is the usual practice, they are not so easy to get at as they would be if they were mounted higher up on the machine.

It is therefore one of the objects of our invention to bring about a new arrangement and interrelationship between the circuit breaker and the distributor in which the circuit breaker mechanism is raised to substantially the level of the distributor, and housing the circuit breaker in a manner to prevent the ingress of deleterious matter.

Another object of our invention is to provide a combination form of circuit breaker and distrib- ,utor of compact and relatively simple design, whereby the cost of construction and assembly may be kept to the minimum.

Another object of our invention is to provide a magneto construction wherein all the moving parts, except the rotor or equivalent structure with its bearings, are removable as a unit without dismantling or disturbing the adjustment of the parts not included in the removable unit.

Another object of our invention is to provide a construction and arrangement of the circuit breaker and distributor which may be assembled with the least number of tools; in fact, only a screw driver being required.

Other and further objects will be apparent to one skilled in the design of generators of the type herein disclosed, from a reading of the specification taken in connection with the annexed drawings, wherein:

Figure 1 is a part-elevational and part-sectional view through a magneto to which our improvements have been applied.

1935, Serial No. 30,656

Figure 2 is a View somewhat similar to the righthand end of Figure 1, but showing the end plate with al1 its associated parts removed from the magneto.

Figure 3 is an end view on the plane 3-3 of Figure 2, showing a manual control for sparktiming purposes. f

Figure 4 is a perspective view of a magneto end plate showing, more particularly, the housing enclosing the circuit breaker mechanism, but without the spark advance and retard mechanism which is shown in Figure 3.

Figure 5 is a front view of the generator with the distributor mechanism removed, but showing the circuit breaker parts.

Figure 6 is a view on the line 6--6 of Figure 5.

Figure 7 is a perspective view of the distributor block.

Figure 8 is a view of the stub shaft carrying the circuit breaker cam and the distributor disc.

Figure 9 is a side or edge view of a stop member used in conjunction with the advance and retard lever.

In the various views, wherein like numbers refer to corresponding parts, I is the body portion of a' magneto, such as illustrated in Dunham et al. Patent 1,887,624, issued November 15, 1932 having a drive shaft 2 and a stationary ignition coil 3 carrying primary and secondary windings. A magnet 4 is used for providing the necessary flux for exciting the windings carried by the coil 3. The drive end plate 5 of the magneto, which may be separate or cast integral with the base or main frame portion I, is provided with a recess B into which projects the tapered end 1 of a coil core 8, the opposite end of which is fastened to the frame of the magneto by a saddle-engaging member 9 tting over a shoulder I0 of the core 8.

Fitting the frame of the magneto is a front end plate II. The inner surface of the front `plate II has an annular ring I2 preferably made integral therewith. Snugly positioned Within the ring I2 is a housing member I3 which, as shown in Figures 1 and 2, has its inner surface nush with the edge of the ring I2, while the inner edge I4 of the housing engages an annular shoulder I5 on the portion I2. The front plate portion I2, as well as the housing member I3, are of considerable depth so as to provide a large supporting surface for the housing member, thereby eliminating all wobble in the mounting for the circuit breaker parts carried by the housing member, as will be later described.

The housing I3 is movably held in its seat, as just defined, by resilient members I6 and I1 (see Figure 3). Preferably these members are notched out at I8 so that the lip portion I9 may be bent slightly inwardly toward the face of the housing I3 to apply a spring pressure thereto to hold the housing movably in position within its seat. Within the housing I3, is mounted, before or after assembly of the housing in its seat, a circuit breaker mechanism consisting of a member 20 (see Figure 5) which has a plurality of elongated holes 2| and lock screws 22, through the cooperation of which the member 20 may be laterally moved for assisting in timing the magneto. On the member 20 is mounted a bracket 23, the same being adjustable thereon by means of screws 24 and 25, the member 23 being provided with a slot 26 whereby the member 23 may be adjusted about the pivot point 25. 'I'he bracket 23 has a lug 21 carrying a contact 28 adaptedv to cooperate with a contact 29 carried on the breaker arm 30 which is pivotally mounted by a stud 3| on the member 23. This construction of circuit breaker is substantially that as described in Patent 2,035,621, issued March 31, 1936, to Harry G. Smith, Jr.

The end plate II carries a support member 32 (see Figure 6) fastened thereto by a stud 33, both of which, however,-that is, the support 32 and the stud 33-are insulated by suitable insulators from the plate II. To one arm 34 of the support 32, is attached an ear 35 of a spring 36, the other end of which is attached to the breaker arm 30. The ear 35 is slotted to receive a fastening screw 31. The slotted ear 35 permits the spring to adjust itself on loosening the screw 31 when making adjustment of the member 20 or the bracket 23. To the stud 33 is fastened, as by means of a clamping nut 33, the primary cable 39 going to an external terminal post 40 which is connected by a cable 4I to the primary winding of the coil 3. The breaker arm 3|] carries the usual bumper 42 adapted to be engaged by a cam 43 mounted on the portion 44 of a stub shaft 45, which carries an anti-friction bearing 46 on the portion 41. The bearing 46 is of the grease-sealed type so the lubricant in the bearing space 96 cannot escape.

It will be noted by reference to Figures 1 and 2, that the bearing 46 is pressed into a recess 48 in the housing member I3. Mounted on the end of the shaft portion 41, adjacent the bearing, is a gear-wheel 50, the same being held in position by a screw 5I and washer 52, it being understood that the end of the shaft 45 is tapped to receive the screw 5I. A spacer or collar 49 engaging the inner race of the bearing 46, positions the gear- Wheel 50.

It will be noted that the cam 43 has a hub portion 53 extending into the recess or chamber occupied by the bearing 46. The cam 43 and the hub 53 are made integral from self-lubricating metal which preferably consists of finely divided metal powder pressed into a more or less porous mass and then heat-treated. Thus the porosity of the cam will pick up lubricant from the bearing chamber, as this chamber is packed with grease when the device is assembled, and some of this lubricant is very slowly transferred to the wearing surface of the cam 43. If desired, the bearing chamber may be provided with an oil duct leading to the exterior of the magneto, so that oil may be passed to the bearing.

Where it is desired to control and vary the adjustment of the circuit breaker, a plate 54 may be fastened to the face of the lhousing member I3 in any satisfactory manner as by rivets 55. Ihe plate 54 has a pair of spaced fingers 56 and 51, between which is positioned a stud or roller 58 carried on the end of a lever 59 which projects through a hub 60 on the front plate II, and to which may be attached a control lever 6I. The plate II is provided with a pair of bosses 62 and 63 which are tapped at 64 to receive a stop plate 65 that may be mounted on either of the bosses 62 or 63 as desired.

If the magneto is to be used as a fixed spark machine, the lower part of the plate II will be constructed as shown in Figure 4; in fact, the circuit breaker housing I3, since it does not have to be moved, may be made integral with the front plate II.

The outer end portion 66 of the stub shaft 45 is adapted to receive a distributor disc 61 which has a hub 68, within which is fastened, as by being moulded therein, a collar 69. The end of the shaft 45 has a slot 10 therein to receive a portion of the distributor disc 61, whereby the disc may be driven by the shaft 45. The distributor disc 61 carries a current-distributing finger 1I which preferably has a resilient portion 12 adapted to engage a contact 13 which is preferably of a suitable grade of carbon mounted in the end of a screw 14 which is removably held, for the purpose of renewal, by a bushing 15 formed integrally with a distributor block 16 and contacting with a metallic member 11 which is fastened to a metallic cup-shaped member 18, the cup 18 being adapted to receive a. resilient clip 19 carried by the high-tension lead 80 coming from the coil 3.

The shaft 45 is preferably made with a collar 8| to act as a backing member for a metallic disc 82 which serves as one electrode of a spark gap, the other electrode being a metallic pin 83 carried by the distributor disc 61. The distributor block 16 has the necessary number of terminals 84 carrying brushes 85 to cooperate with the distributor disc 61 and finger 1I, whereby current is distributed to the various high-tension leads (four being provided for on the block shown) running from the magneto to the engine.

As indicated in Figures 3 and 4, the plate II has a hole 86 therein to receive a hollow projection 81 extending from the distributor block 16 to receive the cable and spring clip 19. The distributor block 16 may be held to the plate Il in any satisfactory maner as by studs or screws passing through screw-holes 88 in the bosses 89.

The inner surface of the distributor disc 61 has a series of convolutions or corrugations 90 moulded therein to prevent surface leakage. Likewise, the inner face of the distributor block 16 between the brushes 85 is preferably serrated as indicated at 9| for the same purpose.

By reference to Figure 1, it will be seen that the gear 5U is driven by a pinion 92 carried on the rotor or rotating member. Also mounted in the lower portion of the magneto housing, is a bracket 93 which carries a condenser 94 connected by a conductor or cable 95 to the grounding post or terminal 40.

It is to be understood that sufficient slack is left in the cables 39, 4I and 95, running to the terminal post 40, so that the front plate II can be removed from the frame work of the magneto a sufficient distance to disconnect these cables from the stud or terminal 40, whereby the plate II with the mechanism carried thereby can be removed entirely from the magneto without disturbing the coil and the rotating portion of the machine. Of course the distributor block 16 and the distributor disc 61 may be removed independentA of the other parts. Likewise, the contact-carrying members and other operative parts of the circuit breaker may be removed independently or as a unit assembly. Furthermore, the complete unitary assembly of gear, shaft, cam, circuit breaker and distributor need not necessarily include a complete removable front plate, as the magneto frame may be constructed so as to have the unitary structure applied in a different manner than shown, the drawings merely showing a preferred form of assembly.

A pigtail connector 91 may or may not beused as an electrical connecting bridge between the ring I2 and housing member I3.

The cam 43 need not necessarily have an extension such as 53 running into the bearing chamber, as other means for lubricating its surface may be provided. For example, a wick may be used which extends into the bearing chamber for drawing lubricant from the chamber to the cam. Furthermore, the cam need not be of the special construction heretofore specified, but if the cam is made in the usual way; that is, from a piece of solid, non-porous material, the wick will then carry the lubricant to the cam surface.

From what has been said, it will be seen that several novel features are incorporated in the construction herein described, all of which are intended to be covered by the appended claims.

What we claim is:

1. For an ignition generator having a relatively stationary induction coil with means for sending flux therethrough; a member adapted to constitute a partial enclosure for the generator, and itself carrying a housing portion, a distributor block having spaced contacts and forming with said housing portion a chamber, a shaft carried by said housing portion, a distributing disc carried by said shaft and having a contact in cooperative relation with the contacts in said block, circuit breaker mechanism mounted on said housing portion within said chamber, a cam carried by said shaft to cooperate with said breaker mechanism, means carried by said shaft outside of and adjacent said housing portion for turning said shaft, and means for making electrical connections to the proper parts of the circuit breaker and distributor block.

2. A construction for an ignition generator as set worth in claim 1, further characterized in that said housing portion has an annular recess carrying a lbearing for the shaft, and the cam has a hub projecting into the bearing recess, the cam and hub being of a material which will absorb lubricant from the bearing recess and pass the same to the wearing surface of the cam.

3. A construction for an ignition generator as set forth in claim 1, further characterized in that the shaft carries a safety gap electrode between the cam and distributor disc with a cooperating gap electrode carried by said disc.

4. A construction for an ignition generator as set forth in claim 1, further characterized in that the generator enclosure member has a hub carrying an advance lever, while said housing portion has a plate attached thereto having a pair of laterally spaced fingers to receive an element on the advance lever, said enclosure member also having a pair of spaced bosses for carrying a stop for said lever.

5. A construction for an ignition generator as set forth in claim 1, further characterized in that said housing portion carries an insulated support lug for receiving a slotted ear of a spring which connects with the movable arm of the circuit breaker.

6. A construction for an ignition generator as set forth in claim 1, further characterized in that said housing portion has an annular recess carrying a bearing for the shaft, and the cam has a hub projecting into the bearing recess, the cam and hub being of a self-lubricating metal consisting of finely divided metal powder compressed and heat-treated.

7. A construction for an ignition generator as set forth in claim 1, further characterized in that said housing portion has an annular recess carrying a bearing for the shaft, and the cam is provided with means extending into the bearing recess and adapted to pick up lubricant therefrom and convey it to the cam.

8. A front end construction for a magneto generator having a main rotatable member and a gear thereon and also a stationary induction coil, said construction including a part carrying a housing portion and a distributor block, together forming a chamber for; a circuit breaker mechanisrn including a cam, a distributor disc having a distributing finger, a common shaft for the cam and disc, the shaft being carried by said housing portion; and a gear on the generator' end of the shaft to function with said gear on the main rotatable. member of the generator.

9. A front end construction for a magneto generator as set forth in claim 8, further characterized in that said generato-r part has an annular recess of considerable depth while the said housing portion is also of substantial depth, whereby a large support surface is afforded the housing portion, said generator part carrying below said chamber an advance lever mechanism coupled to said housing portion.

l0. A front end construction for a magneto generator as set forth in claim 8, further characterized in that the housing portion has a centrally located recess carrying a bearing for the shaft, the cam having a hub projecting through the wall of said bearing recess for the purpose described, the generator end of the shaft being arranged to receive a holding device to hold the gear on the shaft and the shaft in position.

11. A front end construction for a magneto generator as set forth in claim 8, further characterized in that said generator part has a hole therein and the distributor block has a hollow projection adapted to go through said hole and extend a considerable distance toward the generator induction coil, the high tension lead of which is provided with a clip to contact with a cooperative contact within said blo-ck finger.

12. A front end construction for a magneto generator as set forth in claim 8, further characterized in that the arrangement is such that when the distributor block is removed, the distributor disc may then be removed to expose the circuit breaker parts carried by said housing portion.

13. A front end construction for a magneto generator as set forth in claim 8, further characterized in that the lower end of said generator part forms a closure for a condenser carried on a bracket attached to the frame of the generator.

14. A front end construction for a magneto generator as set forth in claim 8, further characterized in that the distributor block carries a centrally arranged readily renewable contact cooperating with the distributing finger on the distributor disc.

15. A front end construction for a magneto generator, including a detachable plate carrying the following instrumentalities: a housing portion and a distributor block having spaced contacts, said housing portion and block being disposed on the plate in the same axial alignment and forming a chamber, a shaft and bearing therefor carried by the housing portion, circuit breaker parts mounted within and on said housing portion, a cam on the shaft for actuating the circuit breaker, a distributing device on the shaft for cooperation with said block contacts, and a gear on the end of the shaft outside the chamber.

16. A front end construction for a magneto generator as set forth in claim 15, further characterized in that said instrumentalities include an advance and retard mechanism carried at the bottom of the plate and operatively connected t0 said housing portion.

17. A front end construction for a magneto generator as set forth in claim 15, further characterized in that said plate and parts carried thereby may be removed as a unit from the generator without disturbing the main rotating part of the generator or the induction coil.

18. In a magneto electric generator having a main rotatable member with a ldriving gear thereon, a drive end plate having a tapering wall recess therein, an induction coil having a core with a tapered end to t in said recess and a clamp engaging the opposite end of the coil core to hold the coil and core in operative position in the generator, a detachable front end plate carrying on its upper portion a housing member and a distributor block having spaced contacts and a projecting finger having an interior contact the finger extending through the plate toward said coil, said coil having its outgoing hightension lead provided with means to engage in a sliding fit said finger interior Contact, a circuit breaker, a. shaft and cam thereon carried by said housing member, a distributor disc and finger carried on the end of the shaft in cooperative relation with said block contacts and a gear on the end of the shaft toward said coil adapted to engage the gear on the main rotatable member of the generator.

19. In a magneto electric generator having a relatively stationary coil with high and low tension windings thereon and core and a main rotatable member for directing magnetic flux through the coil core, said coil being held in position by the following means; a recess having tapering walls in the drive end portion of the frame, a tapered end of the core to fit said recess and a clamp engaging the opposite end of the core to draw it into position on the frame, a detachable front end plate carrying on its upper portion a housing member and a distributor block having spaced distributing contacts and a distribution contact, means for connecting the high tension winding to said distribution contact, a circuit breaker, a shaft and cam thereon carried by said housing member, a distributor disc and finger carried on the shaft in cooperative relation with said distribution contact and block distributing contacts, and means on the shaft toward said coil adapted to be driven from said main rotatable member.

20. For an ignition generator having a relatively stationary induction coil with means for sending flux therethrough; a front plate carrying a housing member on one side thereof and a distributor block having spaced contacts on the other side forming with said housing member a chamber, a shaft carried by said housing member, a distributing disc on the end of said shaft having a finger in cooperative relation with the contacts in said block, circuit breaker mechanism mounted on said housing member Within said chamber, a cam carried by said shaft to cooperate with said breaker mechanism, means on the generator end of said shaft outside of but closely adjacent said housing member for turning said shaft, and means for making electrical connections to certain of the circuit breaker parts and distributor block.

LE ROY S. DUNHAM. HARRY G. SMITH, JR. 

